As a kid, the son of immigrants went to the Japantown arts theater to watch his older sister in Bondori dance performances. After World War II, he went to community meetings at the theater to demand government redress for the internment of 114,000 Japanese Americans, including his family, during the war. And years later, he watched plays about the painful journey back to Seattle from the camps.

The stage no longer tells those stories. Earlier this year, the Nippon Kan Theatre was sold to ABC Legal Service -- a sign of the times for America's Japanese population.

In Japanese American communities around the nation, local historical and cultural landmarks such as the Nippon Kan Theatre, built in 1909, are disappearing. The Japanese American population is growing slowly, and only a few among the newer generations step up to take over the preservation efforts of the Nissei, the generation born of immigrant parents.

Seattle's historic Japantown, or Nihonmachi, north of South Jackson Street and east of downtown, no longer exists. The stage of Nippon Kan has recently been converted into a dispatch center for ABC Legal Service, with the theater's seating replaced with desks for the messenger service.

"I've seen a lot of touching performances on that stage," said Fuji, 75, the youngest of nine siblings born and raised in the former Japantown, now part of the multiethnic International District. "It's sad to see the theater go because there are hardly any more buildings left from that time."

Nippon Kan Theatre, in the Kobe Park Building at 628 S. Washington St., is a national historic landmark, but there are no regulatory controls at the site as a result of the landmark status.

To understand the challenges facing generations-old Japanese businesses and cultural landmarks, sociologists and demographers point to a stark decline in the population in recent years, even while every other Asian ethnic group has rapidly increased in size.

In Seattle, the number of people of Japanese descent fell 9 percent between 1990 and 2000. The Vietnamese population, which more than doubled in numbers during the decade, replaced the Japanese population as the city's third-largest Asian group.

These trends mirror a national pattern: The number of Japanese fell 6 percent in the decade, becoming the smallest Asian ethnic group in 2000.

The population shift is mainly attributed to lower rates of immigration coupled with higher rates of marriage to non-Japanese.

The first Japanese immigrants arrived in Seattle in the 1880s. Then the flow of immigration ceased after exclusionary immigration laws were passed in 1924. When the immigration restrictions were lifted in 1965, Japan was undergoing an industrial and economic boom, making it less attractive to leave the country.

"Our numbers aren't increasing, but as a whole, Japanese Americans are becoming more assimilated, more diverse and intermarried in a generational way," said Stephen Sumida, a professor of American ethnic studies at the University of Washington.

Indeed, multiethnic families are common among the sensei and yonsei -- the third and fourth generations -- as families have become more dispersed around the region.

Of Frank Fuji's two daughters, one married a Japanese American man and another a white man.

"I was actually shocked when my other daughter married a Japanese man," Fuji said. "This is just the reality -- we are more diverse now."

Slower population growth and the painful dislocation of internment have taken their toll on the community's historical and cultural sites.

In 1908, a government representative from Japan wrote that there were 45 restaurants, 20 barber shops, bathhouses, laundries, 30 hotels and lodging houses, and four groceries among other businesses in Japantown, according to "Seattle's International District" by Doug Chin. Most of those buildings are now gone.

When Frank Fuji was growing up, his father's tavern, Fuji's Tavern, was next to a Japanese-owned confectionary and gift shop. Those stores, on the bottom floor of today's Urban League building at 14th Avenue and Yesler Way, disappeared with the internment.

Today there are only a handful of businesses and cultural buildings that remain. The Panama Hotel on South Main Street is no longer owned by a Japanese American family but still has its historic basement bathhouse. The Uwajimaya Asian Food and Gift Market, which Fujimatsu Moriguchi originally opened on South Main Street after World War II, is still owned by the Moriguchi family, which moved the store to the nearby Uwajimaya Village complex in 2000.

"We don't stick together as much as we used to when we were living closely together and we all knew each other in the neighborhood, went to the same churches and schools and formed our own clubs," said Ed Sugaro, 70, who lived in Japantown after his family returned from the internment camps.

Some argue that the community is still strongly intact, but redefined.

Japanese Americans may not have a physical center as they did in the days before World War II, but the churches, Buddhist temples and few cultural centers such as Keiro Nursing Home have become anchors for the community.

Interracial marriages have also added a major layer of complexity to the more contemporary portrait of Japanese Americans, according to sociologists such as Tetsuden Kashima.

When the number of people who identify themselves as multiple race and of Japanese ancestry are factored into the overall number, the census population figure for Japanese Americans goes up, he said.

"First, we have to define what it means to be Japanese American," said Kashima, a professor in the department of American ethnic studies at the University of Washington.

Kashima said research shows that people of Jewish and Japanese heritage, more than other cultural and ethnic groups, tend to stay associated with ethnic organizations. For Japanese Americans, that means churches, Buddhist temples and such advocacy groups as the Japanese American Citizens League.

So even among the younger generations of Japanese Americans, who may only have one parent of Japanese ancestry, Kashima said those children may still strongly identify with their Japanese cultural background.